/****************************************************************************
 *
 * Copyright 2016 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 *
 ****************************************************************************/
/************************************************************************
 * kernel/sched/sched_getparam.c
 *
 *   Copyright (C) 2007, 2009 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ************************************************************************/

/************************************************************************
 * Included Files
 ************************************************************************/

#include <tinyara/config.h>

#include <sys/types.h>
#include <sched.h>

#include "sched/sched.h"

/************************************************************************
 * Definitions
 ************************************************************************/

/************************************************************************
 * Private Type Declarations
 ************************************************************************/

/************************************************************************
 * Global Variables
 ************************************************************************/

/************************************************************************
 * Private Variables
 ************************************************************************/

/************************************************************************
 * Private Function Prototypes
 ************************************************************************/

/************************************************************************
 * Private Functions
 ************************************************************************/

/************************************************************************
 * Public Functions
 ************************************************************************/

/************************************************************************
 * Name: sched_getparam
 *
 * Description:
 *   This function gets the scheduling priority of the task
 *  specified by pid.
 *
 * Inputs:
 *   pid - the task ID of the task.  If pid is zero, the priority
 *     of the calling task is returned.
 *   param - A structure whose member sched_priority is the integer
 *     priority.  The task's priority is copied to the sched_priority
 *     element of this structure.
 *
 * Return Value:
 *    0 (OK) if successful, otherwise -1 (ERROR).
 *
 *    This function can fail if param is null or if pid does
 *    not correspond to any task.
 *
 * Assumptions:
 *
 ************************************************************************/

int sched_getparam(pid_t pid, struct sched_param *param)
{
	FAR struct tcb_s *rtcb;
	FAR struct tcb_s *tcb;
	int ret = OK;

	if (!param) {
		return ERROR;
	}

	/* Check if the task to restart is the calling task */

	rtcb = this_task();
	if ((pid == 0) || (pid == rtcb->pid)) {
		/* Return the priority if the calling task. */
		param->sched_priority = (int)rtcb->sched_priority;
	}

	/* Ths pid is not for the calling task, we will have to look it up */

	else {
		/* Get the TCB associated with this pid */

		sched_lock();
		tcb = sched_gettcb(pid);
		if (!tcb) {
			/* This pid does not correspond to any known task */

			ret = ERROR;
		} else {
			/* Return the priority of the task */

			param->sched_priority = (int)tcb->sched_priority;
		}

		sched_unlock();
	}

	return ret;
}
